Geographic-based watermarking keys

ABSTRACT

The present invention relates generally to digital watermarking and steganography. In one implementation, a method includes determining a current geographic area of the cell phone; selecting a first digital watermark detector that is associated with the current geographic area, a selected first digital watermark detector being selected from a plurality of different digital watermark detectors; and controlling the cell phone to employ the selected first digital watermark detector to analyze a signal to obtain a digital watermark message there from, wherein the selected first digital watermark detector corresponds to a particular digital watermark embedder that is uniquely assigned to the geographic area.

RELATED APPLICATION DATA

This application is generally related to the present assignee'sfollowing U.S. patent documents: U.S. Pat. Nos. 5,862,260; 6,442,285;6,614,914; 6,804,378; 6,947,571; 6,970,573; Ser. No. 10/686,495(published as US 2004-0181671 A1) and Ser. No. 10/370,421 (published asUS 2004-0049401 A1). This application is also related to assignee'sconcurrently filed U.S. patent application Ser. No. ______ (attorneydocket no. P1171, titled “Safeguarding Private Information throughDigital Watermarking”). Each of the above U.S. patent documents ishereby incorporated by reference.

TECHNICAL FIELD

The present invention relates generally to encoding and decoding objectsbased on location or geographic clues.

BACKGROUND AND SUMMARY

Digital watermarking continues to proliferate. Watermarking hasexperienced success across many boundaries—including geographicboundaries. But sometimes boundaries need to be respected, e.g., interms of content licenses (e.g., content may be licensed for use in onecountry but not another), laws and social rules, and even equipmentmanufacturers (e.g., some manufacturers may want certain types ofwatermark detection while other don't.).

We address geographic boundaries and geographic-based embedding anddetection herein.

Digital watermarking—a form of steganography—is a process for modifyingmedia content to embed a machine-readable code into the content. Thecontent may be modified such that the embedded code is imperceptible ornearly imperceptible to the user, yet may be detected through anautomated detection process. Most commonly, digital watermarking isapplied to media such as images, audio signals, and video signals.However, it may also be applied to other types of data, including textdocuments (e.g., through line, word or character shifting, backgroundtexturing, etc.), software, multi-dimensional graphics models, andsurface textures of objects.

Digital watermarking systems have two primary components: an embeddingcomponent that embeds the watermark in the media content, and a readingcomponent that detects and reads the embedded watermark. The embeddingcomponent embeds a watermark by altering data samples of the mediacontent in the spatial, temporal or some other domain (e.g., Fourier,Discrete Cosine or Wavelet transform domains). The reading componentanalyzes target content to detect whether a watermark is present. Inapplications where the watermark encodes information (e.g., a plural-bitmessage), the reader extracts this information from the detectedwatermark.

The present assignee's work in steganography, data hiding and digitalwatermarking is reflected, e.g., in U.S. Pat. Nos. 5,862,260, 6,408,082,6,614,914, 6,947,571; and in published specifications WO 9953428 and WO0007356 (corresponding to U.S. Pat. Nos. 6,449,377 and 6,345,104). Agreat many other approaches are familiar to those skilled in the art.The artisan is presumed to be familiar with the full range of literatureconcerning steganography, data hiding and digital watermarking. Each ofthe above patent documents is hereby incorporated by reference.

One aspect of the present invention is a watermark detector and embedderthat are closely related to a particular geographical area.

For example, in one implementation, a method is provided including:determining a current geographic area; selecting a first digitalwatermark detection key that is associated with the current geographicarea, a selected first digital watermark detection key being selectedfrom a plurality of digital watermark detection keys; and controlling adigital watermark detector to employ the selected first digitalwatermark detection key to analyze a signal to obtain a digitalwatermark message there from, wherein the selected first digitalwatermark detection key corresponds to a particular digital watermarkembedding key that is uniquely assigned to the geographic area.

In another implementation, a method is provided including, in a cellphone, determining a current geographic area of the cell phone;selecting a first digital watermark detector that is associated with thecurrent geographic area, a selected first digital watermark detectorbeing selected from a plurality of different digital watermarkdetectors; and controlling the cell phone to employ the selected firstdigital watermark detector to analyze a signal to obtain a digitalwatermark message there from, wherein the selected first digitalwatermark detector corresponds to a particular digital watermarkembedder that is uniquely assigned to the geographic area.

In still another implementation, a cell phone is provided including: aradio-frequency transceiver; electronic processing circuitry; andmemory. The memory includes executable instructions stored therein forprocessing by the electronic processing circuitry. The instructionsinclude instructions to: determine a current geographic area of the cellphone; select a first digital watermark detector that is associated withthe current geographic area, a selected first digital watermark detectorbeing selected from a plurality of different digital watermarkdetectors; and control the cell phone to employ the selected firstdigital watermark detector to analyze a signal to obtain a digitalwatermark message there from. The selected first digital watermarkdetector corresponds to a particular digital watermark embedder that isuniquely assigned to the geographic area.

Still another implementation is a method including: receiving a signalfrom a cell phone; determining, based at least in part on the signal,whether the cell phone is physically located in a predetermined homearea; and if not in the predetermined home area, communicating amachine-readable code detector to the cell phone for use as its primarymachine-readable code detector to detect machine-readable code whileoutside of its predetermined home area.

Further aspects, implementations, features and advantages will becomeeven more apparent with reference to the following detailed descriptionand accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates embedding content with different keys according togeographic location.

FIG. 2 illustrates a cell phone including an optical sensor (e.g., adigital camera).

FIG. 3 is a block diagram illustrating a geography based,machine-readable detection.

FIG. 4 illustrates a watermark detection process that evaluates whetheran orientation component is found, prior to key selection and fullwatermark message detection.

FIG. 5 illustrates a network aware presence capability, where a cellnetwork pushes detection information to a cell phone.

FIG. 6 illustrates a key table include multiple, different keys per eachgeographic area.

DETAILED DESCRIPTION

The present assignee has discussed key-based watermarking in a number ofpatent filings, e.g., in U.S. Pat. No. 6,614,914 and pending U.S. patentapplication Ser. No. 11/082,179, filed Mar. 15, 2004 (published as US2005-0271246 A1), which are each hereby incorporated by reference. Forexample, one or more keys may be used to encrypt a message carried by adigital watermark. And another key or set of keys may be used to controlgeneration of a watermark signal or mapping of information bits in amessage to positions in a watermark information signal or carriersignal. A “key” in these contexts serve a function of making a digitalwatermark un-readable to anyone except those having the proper key.

Assignee's U.S. patent application Ser. No. 09/636,102, which claims thebenefit of U.S. Provisional Application No. 60/191,778, discusses adetection system that accommodates different watermark types, perhapseach utilizing different protocols. The watermark protocols provide keysand other parameters specifying how to decode a watermark of a giventype. The above patent documents are each hereby incorporated byreference.

In cases where a media object contains a watermark of an unknown type, amedia file may specify the watermark type, e.g., through a parameter ina file header. The file browser, or other client of the core watermarkmodule, may invoke the appropriate decoder by extracting the typeparameter from the media object and passing it and a reference to themedia file to the core module via an API (application programinterface). The API routes the request to the appropriate core module,which in turn, extracts the watermark message, and returns it to theAPI. The API passes the message to the requesting application.

In the event that a type parameter is not available, the application ordevice processing the object may enumerate through all supportedwatermarking protocols to check if any protocol is present.

One improvement utilizes keys to designate or correspond to differentgeographical areas.

For example, a first (embedding) key is provided for use in a firstgeographical area or market (e.g., France). A corresponding first(detection) key is needed to decode a media signal embedded with thefirst (embedding) key.

A second, different (embedding) key is provided for use in a second,different geographical area or market (e.g., Spain). A correspondingsecond (detection) key is needed to decode a media signal embedded withthe second, different (embedding) key.

The first and second keys are used to seed the same watermark embedder.

For example, with reference to FIG. 1, a first media provider located inFrance embeds first content (e.g., printed materials, audio, videoand/or digital images) with a watermark embedder using the first(embedding) key. While a second media provider located in Spain embedssecond content (e.g., printed materials, audio, video and/or digitalimages) with a watermark embedder using the second (embedding) key.

The first content and second content are distributed for publicconsumption.

In one implementation, watermark detectors are provided alonggeographical boundaries. That is, a first set of detectors are provided,e.g., in France, that include the first detection key. A second set ofdetectors are provided, e.g., in Spain, that include the seconddetection key. The first set of detectors are only able to detectwatermarks embedded with the first embedding key while the second set ofdetectors are only able to detect watermarks embedded with the secondembedding key.

But what if I take my cell phone from Spain, which includes a watermarkdetector including a second detection key, over to France? It seemsunfortunate that my cell phone would not be able to detect watermarks inFrance.

Enter another improvement.

A cell phone shown in FIG. 2 includes a digital watermark detector (notshown in FIG. 2). In a first implementation, a watermark detector isconfigured to cycle through multiple different detection keys. That is,the watermark detector tries to detect a watermark hidden in contentusing a first detection key. If no watermark is recoverable, thewatermark detector employs the second detection key to detect awatermark. If a watermark is still not recoverable, the watermarkdetector moves onto the third detection key, and so on, until awatermark is detected or until all detection keys are exhausted.

(The same watermark detection process is preferably used each time butdetection is altered based on a particular detection key. As discussedabove, the key may be a decryption key which is used to decipher apayload. Or, e.g., the key may provide locations within a carrier signalto look for message information, identify a pseudo-random sequence, etc.Successful watermark detection is contingent upon using the rightdetection key.)

In a second implementation, efficiencies are provided throughprioritizing detection keys based on geographic location.

For example, today's cell phones are sophisticated, some having GlobalPositioning System receivers that provide precise geo-coordinates. Suchlocation information is used to determine which detection key should betried first. The watermark detector or cell phone can maintain a tableor other association (e.g., FIG. 3). Location information is used tointerrogate a registry or table to determine which detection key shouldbe prioritized first. For example, geo-coordinates or other locationinformation may indicate that the cell phone is located in Spain. Theregistry or table indicates that the corresponding detection key is thesecond detection key, which is associated with Spain. Instead of aGPS-equipped cell phone, the cell phone may receive location informationfrom a cell tower or network, which location information is, e.g.,derived based on reception of the cell phone signals at a plurality ofdifferent cell towers. More generally, cell towers can provide generallocation information based on time zones, country or state of operation,tower identifier, etc. (A user can even key in the geographicinformation; but all told, we prefer an automated approach.)

Regardless of the source of the location information, the locationinformation is used by the cell phone to determine a likely—andcorresponding—detection key.

Once a detection key is decided upon, the watermark detector employs thedecided upon key for use with watermark detection.

With reference to FIGS. 2 and 3, a cell phone preferably includes anoptical sensor, e.g., a camera, to capture optical scan data. Capturedoptical scan data—corresponding to watermarked content (e.g., printedmagazine advertisement, etc.)—is provided to the watermark detector(FIG. 3). Location information corresponding to a current location ofthe cell phone is used to select a detection key (Key N) from among aplurality of stored detection keys. The watermark detector employs theselected key during an attempt to detect and read a watermark from thecaptured optical scan data. If successful, the watermark is decoded toobtain a watermark message. If not successful, other keys can be triedfor detection.

The watermark message can be used in a number of applications. Forexample, the watermark message provides a link to related content asdiscussed, e.g., in assignee's U.S. Pat. No. 6,947,571, which is herebyincorporated by reference.

The watermark message can also be used to control use or transfer ofcontent. For example, instead of optically sensing an object, an audioor video file is received by the cell phone. The watermark detectorsifts through the audio or video looking for a digital watermarkembedded therein, based on a key associated with a location of thephone. Once found, the digital watermark is decoded to obtain a message.The message may include or link to usage rights associated with theaudio or video. The usage rights control the cell phone regarding, e.g.,redistribution or copying of the audio or video.

Some digital watermarks include an orientation component. Theorientation component is often helpful in resolving issues such assignal distortion, scaling, rotation, translation, time warping, etc.The curious reader is encouraged to consult assignee's U.S. Pat. Nos.6,975,744; 6,704,869; 6,614,914; 6,408,082; and 5,636,292 for an evenfurther discussion of steganographic orientation techniques andcomponents. Each of these patent documents is hereby incorporated byreference.

One implementation of this aspect of the invention first looks for thepresence of an orientation component before selecting a key or cyclingthrough different watermarking keys. If an orientation component isdetected, a full watermark decoding operation is carried out to detect amessage carried by the watermark. If an orientation component is notdetected, however, key selection and full watermark detection is notcarried out (see FIG. 4). This implementation presupposes that eachembedding technique—each utilizing a different embedding key—embeds anorientation component independent of a specific embedding key. Thisindependence will allow detection of at least the orientation componentregardless of whatever key is used. The message or message locations,etc. of course can be obfuscated through use of an embedding key.

As an alternative embodiment, instead of using different keys to triggerdetection of a particular watermark, different watermark detectors arestored in memory of the cell phone. Each watermark detector correspondsto a particular geographic location. A current location is determinedand that location is used to select a particular watermark detector. Theselected watermark detector is loaded for execution.

In still another embodiment, a cell phone detector receives informationfrom a network as to which detector it should use. This type ofdetection is affectionately referred to as a “network aware presence,”meaning a wireless carrier (or network) “pushes” an appropriate detectorfor that region or geographical area to the cell phone for the purposeof content watermark detection (FIG. 5). The terms “appropriatedetector” in this context refers to a detection key (e.g., a key iscommunicated to the phone), an actual detector (software file) iscommunicated to the phone for downloading, or an index key (e.g., numberor seed) is pushed to the phone which allows the cell phone to access apreviously stored table to identify which detector or detector keyshould be employed. As another example, if a cell phone is normallylocated in Spain, it would have the Spanish content detector loaded orinstalled on the phone; however, when the phone travels to a differentlocation, like the United Kingdom, the “network aware presence”capability of the wireless carrier detects that the phone has nowtraveled to the United Kingdom and the content detector for the UnitedKingdom will be “pushed” automatically (preferably without userintervention) to the phone as a temporary file. The temporary file nowbecomes the primary content watermark detector. (This process can beinitiated by either of the cell phone or network. In the case of thecell phone, it may recognize that it is no longer in its home area andrequest an appropriate detector from the network. Or, in otherimplementations, the network may recognize that the cell phone is aquest or is no longer in its home area and push an appropriatedetector.) Once the user leaves that region, in this case, the UnitedKingdom, the temporary file is automatically deleted or de-prioritizedand the phone's default content detector is reloaded or activated as theprimary content detector.

In another embodiment, multiple different keys are assigned to eachgeographic location (FIG. 6). For example, Spain may have 10 or morekeys assigned to it, while France may have a different set of 10 or morekeys assigned to it. In this way, if a particular key is compromised,there are still other keys available for that geography. Whenprioritizing keys for detection, all keys for a particular geography canbe cycled through first or subsets of keys can be identified for higherprioritization.

While the above embodiments have been described as operating in a cellphone environment, the present invention is not so limited. Indeed, manyother computing environments will benefit from these techniques. Forexample, PDAs, laptops, desktops, etc. that are able to determine alocation of the device will similarly benefit.

Also our techniques of assigning a key or detector based on geographiclocation can apply to other machine-readable symbologies as well. Forexample, consider 2D barcodes. A barcode can be encrypted based ongeographic area. For example, a first encrypting key is assigned to afirst area and a second encrypting key is assigned to a second,different area, and so on. A detection process determines a currentgeographical area and finds a detector or decryption key that isassociated with the area. A determined detector or decryption key isused to decode or decrypt the 2D symbology. (All told, however, weprefer steganography and digital watermarking, e.g., for theirimperceptibility in many applications.)

A few combinations, in addition to those in the claims and thosedescribed above, are as follows:

A1. A cell phone comprising:

a radio-frequency transceiver;

electronic processing circuitry; and

memory, wherein said memory comprises executable instructions storedtherein for processing by said electronic processing circuitry, saidinstructions comprising instructions to:

-   -   receive information related to a current geographic area in        which the cell phone is located;    -   select, using at least a portion of the received information, a        first digital watermark detector that is associated with the        current geographic area, a selected first digital watermark        detector being selected from a plurality of different digital        watermark detectors; and    -   control the cell phone to employ the selected first digital        watermark detector to analyze a signal to obtain a digital        watermark message there from, wherein the selected first digital        watermark detector corresponds to a particular digital watermark        embedder that is uniquely assigned to the geographic area.

A2. The cell phone of Al wherein the different digital watermarkdetectors are distinguished from one another based on differentwatermark detection keys.

A3. The cell phone of Al wherein the cell phone further comprises aglobal positioning system (GPS) receiver and the current geographic areais determined from information received by the GPS receiver.

A4. The cell phone of Al wherein the current geographic area isdetermined from information obtained from a network communicating withthe cell phone via the radio frequency transceiver.

Concluding Remarks

Having described and illustrated the principles of the technology withreference to specific implementations, it will be recognized that thetechnology can be implemented in many other, different, forms. Toprovide a comprehensive disclosure without unduly lengthening thespecification, applicants hereby incorporates by reference each of theU.S. patent documents referenced above.

The methods, processes, components, modules, generators and systemsdescribed above may be implemented in hardware, software or acombination of hardware and software. For example, the watermark datadecoding or permutation processes may be implemented in a programmablecomputer or a special purpose digital circuit. Similarly, watermark datadecoding or cryptographic permutation process may be implemented insoftware, firmware, hardware, or combinations of software, firmware andhardware.

The methods, components and processes described above may be implementedin software programs (e.g., C, C++, Visual Basic, Java, executablebinary files, etc.) executed from a system's memory (e.g., a computerreadable medium, such as an electronic, optical or magnetic storagedevice).

The section headings are provided for the reader's convenience. Featuresfound under one heading can be combined with features found underanother heading. Of course, many other combinations are possible giventhe above detailed and enabling disclosure.

The particular combinations of elements and features in theabove-detailed embodiments are exemplary only; the interchanging andsubstitution of these teachings with other teachings in this and theincorporated-by-reference U.S. patent documents are also contemplated.

1. A method comprising: determining a current geographic area; selectinga first digital watermark detection key that is associated with thecurrent geographic area, a selected first digital watermark detectionkey being selected from a plurality of digital watermark detection keys;and controlling a digital watermark detector to employ the selectedfirst digital watermark detection key to analyze a signal to obtain adigital watermark message there from, wherein the selected first digitalwatermark detection key corresponds to a particular digital watermarkembedding key that is uniquely assigned to the geographic area.
 2. Themethod of claim 1 wherein each of the plurality of digital watermarkdetection keys corresponds to a unique geographic area.
 3. The method ofclaim 1 further comprising controlling the digital watermark detector toemploy a different digital watermark detection key to analyze the signalto obtain the digital watermark message there from when the message cannot be obtained though use of the first digital watermark detection key.4. The method of claim 1 wherein the key comprises a decryption key. 5.The method of claim 1 wherein the key comprises a mapping of hidinglocations.
 6. The method of claim 1 wherein said method is carried outon a cell phone.
 7. The method of claim 6 wherein the cell phonecomprises a global positioning system (GPS) receiver and the currentgeographic area is determined from information received by the GPSreceiver.
 8. The method of claim 6 wherein the current geographic areais determined from information obtained from a network communicatingwith the cell phone.
 9. The method of claim 1 wherein the digitalwatermark comprises an orientation component.
 10. The method of claim 9wherein prior to analyzing the signal to obtain a digital watermarkmessage, said method comprises determining whether the signal comprisesan orientation component, wherein analyzing the signal to obtain adigital watermark message is only carried out when the orientationcomponent is detected.
 11. A cell phone comprising memory includinginstructions stored thereon, said instructions comprising instructionsto carry out the method of claim
 21. 12. The method of claim 21 whereinthe signal comprises optical scan data representing at least a portionof a physical object.
 13. The method of claim 21 wherein the signalcomprises at least one of audio and video.
 14. A method comprising: in acell phone: determining a current geographic area of the cell phone;selecting a first digital watermark detector that is associated with thecurrent geographic area, a selected first digital watermark detectorbeing selected from a plurality of different digital watermarkdetectors; and controlling the cell phone to employ the selected firstdigital watermark detector to analyze a signal to obtain a digitalwatermark message there from, wherein the selected first digitalwatermark detector corresponds to a particular digital watermarkembedder that is uniquely assigned to the geographic area.
 15. Themethod of claim 14 wherein the different digital watermark detectors aredistinguished from one another based on different watermark detectionkeys.
 16. The method of claim 14 further comprising carrying out anaction based at least in part on an obtained digital watermark message.17. The method of claim 14 wherein the cell phone comprises a globalpositioning system (GPS) receiver and the current geographic area isdetermined from information received by the GPS receiver.
 18. The methodof claim 16 wherein the current geographic area is determined frominformation obtained from a network communicating with the cell phone.19. A cell phone comprising memory including instructions storedthereon, said instructions comprising instructions to carry out themethod of claim
 34. 20. A method comprising: receiving informationindicating a geographical area; with reference to at least a portion ofthe information indicating a geographical area, selecting amachine-readable indicia detector that corresponds to the informationindicating a geographical area; processing machine-readable indicia withthe selected machine-readable indicia detector to obtain a plural-bitmessage; and carrying out an action using the plural-bit message. 21.The method of claim 20 wherein the information indicating a geographicalarea is received from a global positioning system (GPS) receiver. 22.The method of claim 20 wherein a cell phone executes said method. 23.The method of claim 22 wherein the information indicating a geographicalarea is received from a network communicating with the cell phone. 24.The method of claim 20 wherein the machine-readable indicia comprises anencrypted 2D-barcode.
 25. The method of claim 25 wherein the selectedmachine-readable indicia comprises at least a decryption key thatcorresponds to encryption used to encrypt the encrypted 2D-barcode. 26.The method of claim 20 wherein the machine-readable indicia comprisessteganographic encoding.
 27. A method of comprising: receiving a signalfrom a cell phone; determining, based at least in part on the signal,whether the cell phone is physically located in a predetermined homearea; and if not in the predetermined home area, communicating amachine-readable code detector to the cell phone for use as its primarymachine-readable code detector to detect machine-readable code whileoutside of its predetermined home area.
 28. The method of claim 27wherein the machine-readable code detector comprises a detector foranalyzing optical scan data captured by the cell phone.
 29. The methodof claim 28 wherein the machine-readable code comprises a 2D barcode.30. The method of claim 28 wherein the machine-readable code comprisesdigital watermarking.
 31. The method of claim 27 wherein themachine-readable code comprises a code hidden in audio or video.
 32. Themethod of claim 27 wherein the detector comprises at least one of adetection key and a software detector.